Containers can be used to transport and/or store flowable materials. Flowable materials may include liquids such as water, fuel, or other chemicals, and may also include any other material capable of flowing such as sand, grain, slurry, etc. Several significant challenges that are not present with bulk dry goods arise when transporting flowable materials. These include, among others, the higher weight-to-volume ratio of flowable material compared to that of bulk dry goods, the flowable nature of flowable materials, which requires an impermeable containment vessel of adequate strength, the extreme flammability of some flowable materials such as gasoline and other fuels and chemicals, and the lack of vertical and horizontal linking and hoisting components in flowable materials vessels (or tanks).
In many cases, the payload (weight) limits of a transport apparatus (e.g., ship, truck, trailer, aircraft (fixed and rotary wing), rail car, parachute drop, and low altitude parachute extraction systems (LAPES)) constrain the amount of flowable material that can be transported. In contrast to dry goods containers, which typically exceed volume limits before they exceed weight limits, flowable material containers often achieve the maximal weight before they reach the maximal volume. In order to increase the quantity of flowable material transported without increasing the payload limit of the transport apparatus, the tare weight of the container must be decreased.
Steel and aluminum containers characterized by a vessel having a round cylindrical shape are known in the art and can be used to transport and/or store fuel. While these types of containers may be fire and heat resistant and prevent significant permeation of fuel vapors, the heavy weight of the steel or aluminum constrains the amount of fuel that can be transported. Furthermore, use of a round cylindrical vessel (due to its non-orthogonal morphology) does not allow for efficient integration of the vessel between different components of the transport infrastructure used in inter-modal transport, such as ships, trucks, trailers, aircraft, and rail cars, whose cavities are typically orthogonal. In other words, significant amounts of space are wasted between the cylindrical vessel and the smallest box-shaped space (right cuboid envelope) within which the cylindrical vessel could fit. Additional problems with containers having round cylindrical vessels include the inability to stack them and the lack of corner fittings to secure them within the cavities of ships, trucks, trailers, aircraft, rail cars, etc.
Additionally, lack of corner fittings for hoisting cylindrical vessel containers limits their use in any settings where lifting, loading, unloading, or otherwise moving by cranes, spreaders, and aircraft can be required, as is typically the case for moving larger containers that meet International Organization for Standardization (ISO) standard 668:1995 (i.e., ISO containers). In military settings, in addition to the above methods of hoisting, sling loads may be used, which become more cumbersome with containers lacking corner fittings. Employing a box-shaped (right cuboid) steel cage or frame surrounding a cylindrical steel vessel and equipping it with corner fittings to allow linking and stacking of cylindrical vessel containers is known. However, the steel cage or frame increases the container's total tare weight and, thus, diminishes the quantity of the asset (e.g., gasoline or other flowable material) that can be transported. Therefore, while steel cages or frames promote transportability, they further limit the capacity of a cylindrical vessel container (assuming the payload weight limit of the transport apparatus remains the same).
Polyethylene containers are known in the art and can reduce the weight of a container below that of a steel container. However, existing polyethylene containers have several drawbacks. They are not compatible with certain ISO standards and therefore are not compatible with certain aspects of existing ISO transport infrastructure, vehicles and platforms. They typically do not have corner fittings to allow hoisting and securing. They are cylindrical, like their steel counterparts, and thus not made to be stacked efficiently.
In the military, there is a significant burden of transporting liquids, especially fuel and water. A Nov. 10, 2009 article in the Wall Street Journal titled “Fuel Fighter: The U.S. Military Is a Gasoline Glutton” identified fuel supply lines as being costly and dangerous. The article cites a study by consulting firm Deloitte which “suggests that the Army reduce the need for fuel convoys.” According to “Battlefield Renewable Energy” by Adams et al in the Joint Force Quarterly (issue 57, 2010), “through analysis, MNF-W [Multi-National Force-West in Iraq] determined that most casualties occurred during the movement and delivery of fuel to the various combat outposts and bases throughout the division's area of operations.”
An improvement in fuel efficiency by vehicles, generators and other equipment, vehicles, or infrastructure requiring fuel, is often recommended as a means for reducing fuel convoys, and, hence, the burden of transporting fuel. However, to reduce the number of fuel convoys, increasing the volume of fuel transported per transport apparatus (e.g., per truck or trailer) will have significantly greater effect on lessening the burden of transporting fuel than improving the military's overall fuel efficiency. Specifically, studies by the inventors of the utilization certain embodiments of the present invention within the US military show that increasing the volume of fuel transported per transport apparatus will decrease the economic costs by 18% to 40% while improving the military's overall fuel efficiency is only expected to result in 3% economic cost savings. Increasing the volume of fuel that can be transported per transport apparatus has been overlooked, perhaps due to difficulties in calculating the Fully Burdened Cost of Fuel (FBCF), i.e., the cost for fuel transport in addition to the fuel commodity itself, which provides a metric that can be used in assessing the casualties that could be prevented and the monetary savings that could be achieved as a result of using an alternate transportation system for transporting fuel. According to the Defense Science Board, as stated in an article in the April 2010 issue of National Defense, the Pentagon has not yet established “reliable methods for measuring the ‘fully burdened’ cost of fuel.” An analogous, but different, calculation is the Fully Burdened Cost of Water (FBCW), i.e., the cost for water transport in addition to the water itself, which provides a metric that can be used in assessing the casualties that could be prevented by and the monetary savings of using an alternative transportation system for water.
In the military, there is a need for flexibility and efficiency, and for accommodation of quickly changing plans. Large containers transport more material or liquid per load with less loading and unloading of containers. However, smaller containers allow for more flexibility with smaller amounts of material being collected or delivered to different locations. There is a need for a modular system of containers to enable the delivery of a range of load sizes (small to large, including intermediate loads), whereby small containers are linked together to create increasingly larger increments of load. There is also a need for a modular system of containers to enable the delivery of a range of load sizes (small to large, including intermediate loads), whereby smaller load sizes of flowable materials can be delivered quickly by disengaging modular containers from one another as opposed to transferring (e.g., pumping) flowable material from a larger container to a smaller container, a process that can introduce contamination in addition to expending time. Further, there is a need for a modular system of containers to enable the delivery of a diversity of materials whereby containers, which may be built from different types of materials that can transport and store a range of liquid and dry assets, are linked together to create mixed loads. Such a modular system achieves the benefits of easily transporting larger volumes when large volume transport is required, smaller volumes when small volume transport is required, and homo- and heterogeneous loads, and is compatible with a hub and spoke model of transport where large and then progressively smaller loads are delivered to hubs of diminishing sizes (in terms of the volume of load delivery requested).
Therefore, there is a need for an improved container being able to transport a greater quantity of flowable material per load than prior containers of the same orthogonal envelope, being integrated with existing transportation infrastructure, vehicle and equipment requirements, having similar fire and heat resistant properties that are observed for steel and aluminum containers, being self-sealing upon puncture or cracking to prevent the loss of flowable material and to avoid injury, and being modular so as to accommodate the dynamic requirements of load size and type of modern civilian and military logistics operations for flowable material.